Blank firing attachment

ABSTRACT

A blank firing attachment is provided for automatic weapons which comprises a cylindrical member one end of which is open for slideable mounting on the muzzle end of the weapon barrel. A collet and split ring arrangement is associated with the open end of the member and is adjustable with respect thereto to hold the attachment on the muzzle end and effect substantial sealing engagement therewith whereby the expanding gases incident to firing blank ammunition are confined within the barrel for accomplishing automatic operation in a manner well-known in the art. The housing is also provided with vent means for controlled release of the gases within the barrel.

ite tates Patent [191 El 111 3,732,77 Snodgrass 51 May 15, 1973 [54]BLANK FIRING ATTACHMENT FOREIGN PATENTS OR APPLICATIONS 5] Inventor:Robert gr np r 627,198 1/1963 Netherlands ..42/79 Iowa [73] Assignee:The United States of America as pmimry E'fam.1erBenJamm A'BmchehASSISICZIII lz.\'ammerHarold Tudor represented by the Secretary of theA)rn)v Harr M Slra Ovitz et ll Army, Washington, DC. y g c [22] Filed:Sept. 17, 1971 [57] ABSTRACT [21] Appl. No.: 181,486 A blank firingattachment isprovided for automatic weapons which comprises acylindrical member one [52] U.S. Cl. ..89/I4 E end of whlch Open forShdeable mounting muzzle end of the weapon barrel. A collet and spl1t[51] Int. Cl.. ..F4lf 17/00 fin arran emem is associated with the 0 enend of 58 Field of Search ..89/14 R, 14 A, 14 B, g g t p 89/14 C 14 D 14E 14 42/79 the member and IS ad ustable with respect thereto to hold theattachment on the muzzle end and effect substantiai sealing engagementtherewith whereby the ex- [56] References cued panding gases incident tofiring blank ammunition are UNITED STATES PATENTS coniined within thebarrel for accomplishing automatic operation in a manner well-known inthe art. 1137304 6"964 Harvey E The housing is also provided with ventmeans for con- 3,440,924 4/1969 Sawyer ..89/l4 E ll d release of thegases within the barrel. 2,330,210 9/1914 Garand ..89/l4 E 8 Claims, 4Drawing Figures BLANK FIRING ATTACHMENT BACKGROUND OF THE INVENTION Thepresent invention relates to an attachment for weapons, and moreparticularly to a blank firing attachment for effecting automaticoperation of weapons.

In the art of automatic weapons, utilization of gas pressures within thebarrel is relied upon to effect automatic operation in a mannerwell-known in the art. If blank ammunition is used in such weapons, suchas in the case of training operations to simulate actual combatconditions, there is no projectile propelled through the barrel whichenables the gas system to function. Accordingly, a blank firingattachment is applied to the muzzle end of the barrel, the purpose ofwhich is to take the place of the projectile function and to enable gaspressures to build up in the barrel sufficient to operate the weaponcontinuously and automatically thereby simulating sustained fireconditions.

Although blank firing attachments are not new to the art, many are foundobjectionable from the standpoint of safety, ease of application to orremoval from the weapon barrel, not universally applicable, or they arecomplicated in structure, or cause unnecessary damage to a gun barrel.

Accordingly, it is a primary object of the present invention to providea simple, yet highly effective, blank firing attachment for an automaticweapon.

It is also an object of the present invention to provide a blank firingattachment which can be easily attached to and detached from a weaponbarrel.

Another object of the present invention is to provide a blank firingattachment which is universally applicable to and particularly adaptedfor use with automatic weapons.

A further object of the present invention is to provide a blank firingattachment for automatic weapons which conforms to maximum safetyrequirements and minimizes damage to the barrels of the weapons it isused with. 1

Still another object of the present invention is to provide a blankfiring attachment for automatic weapons which is of simple structure,conducive to mass production, and yet is relatively inexpensive tomanufacture.

SUMMARY OF THE INVENTION In accordance with the present invention, ablank fir- 'ing attachment for automatic weapons is provided whichcomprises a cylindrical member having one end open for slideablyreceiving either the muzzle end of a weapon barrel or other attachmentsassociated therewith. An annular shoulder associated with the barrelmuzzle end is utilized to attach the unit to the barrel. Split ringmeans is disposed in abutment with the open end of the cylindricalmember. A collet encompasses the split ring means and a portion of theopen end and is adjustably arranged for axial movementrelative to thecylindrical member. The internal surface of the collet is provided witha cam surface which tightens the split ring into sealing engagement withboth the shoulder and the open end of the cylindrical member. Vent meansis disposed in a cylindrical member wall for controlled release ofexpanding gases within the barrel and cylinder incident to firing theweapon.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features characteristic ofthe present invention, as well as additional objects and advantagesthereof, will be understood better from the following description whenread in connection with the accompanying drawing in which:

FIG. 1 is a central, longitudinal section of a preferred embodiment ofthe present invention as applied to the muzzle end of a weapon barrel,the parts being shown in an unlocked position;

7 FIG. 2 is a view similar to FIG. 1 but showing the parts in a lockedposition;

FIG. 3 is a side view of a single element lock ring for the blank firingattachment, a portion thereof being shown in cross section; and

F IG, 4 is a side view of an alternate form of lock ring, a portionthereof being shown in cross section.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring more particularly to thedrawing, wherein similar reference characters have been used todesignate corresponding parts throughout, FIGS. 1 and 2 show a preferredembodiment of a blank firing attachment 1 in accordance with the presentinvention, as applied to the muzzle end of an automatic weapon barrel 3.

The preferred embodiment of blank firing attachment 1 is shown appliedto a conventional flash suppressor 5 which is threadably engaged on themuzzle end of the barrel 3. The flash suppressor includes the customaryradial openings 7 and an axial opening 9 in the end 11 thereof whichfunction in a manner wellknown in the art. In order to effect automaticoperation of a weapon using blank ammunition, it is necessary to closeoff these openings. This is accomplished by employing a cap-like body 13in the form of a cylinder having one end 15 closed and the opposite end17 open. The length of the cap-like body is at least coextensive withthe radial openings 7 from the end 11 of the flash suppressor 5. Theinside diameter of thecaplike body is greater than that of thesuppressor so that it can be slideably disposed thereover.

The flash suppressor 5 is provided with a circumferential groove 19 inits outer surface, adjacent to but rearwardly of the radial openings andwhich is utilized to seal and fasten the blank firing attachment ontothe flash suppressor. The groove 19 provides a front shoulder 20 and arear shoulder 22, and the side 24 of the front shoulder remote from themuzzle end of the barrel cooperates with a split ring 31, in a mannermore particularly described hereinafter. A similar groove would berequired adjacent to the muzzle end of a barrel in the event no flashsuppressor was associated therewith.

On the external surface 21 of the cap-like body 13, adjacent to the openend 17 thereof, there is provided a shoulder 23 having the cylindricalouter surface thereof threaded. A collet 25 has the internal surface 27thereof threadedly engaged with the shoulder 23 for adjustment axiallywith respect to the cap-like body 13. Adjacent to the rear end of thecollet, remote from its engagement with the shoulder, a portion 29 ofthe internal surface is gradually reduced in diameter to provide a camsurface. A lock ring 31 is disposed within the collet 25 which is of adiameter slightly greater than the external diameter of the flashsuppressor so that it can be slipped thereover in assembly. The lockring is disposed in abutment with the open end 17 of the caplike body 13and it is provided with a diagonal cut or slit 33 to facilitate reducingits diameter under the influence of the collet cam surface 29. Althoughthe lock ring may be of a single ring type having a circular crosssection, as shown in FIG. 3 of the drawing, an alternate embodiment oflock ring which is a split ring 35, as shown in FIG. 4, can also beused. In the latter case, each half has a semi-circular cross sectionand the respective flat sides 37 of the two ring halves are disposedadjacent to each other. Each one of the ring halves is provided with adiagonal cut or slit 39 the same as cut 33 in the single ringembodiment. Preferably, the respective cuts in the two halves should bespaced apart in order to provide a more effective gas seal.

The cap-like body 13 is provided with a small hole 41 in the closed end15 thereof. It is disposed preferably away from the center line of thebore axis so that expanding gases do not have an exit path straightthrough. The hole 41 is of a size which will effectively reduceexpanding gas pressures within the barrel incident to blank firing butmaintain sufficient pressure to sustain automatic fire of the weapon ina manner well-known in the art.

Application of the blank firing attachment to the barrel of a weaponutilizing a flash suppressor is as follows. The blank firing attachmentis assembled with the collet 25 threadedly engaged with the cap-likebody shoulder 23, and with the lock ring loosely disposed within thecollet, as shown in FIG. 1 of the drawing. The as sembly is mounted overthe flash suppressor sufficiently to dispose the lock ring axiallyopposite the suppressor groove 19 and in abutment with the open end 17of the cap-like body. The collet is rotated relative to the cap-likebody thereby to advance it forwardly. This movement of the colletengages the internal cam surface 29 thereof with the lock ring to reducethe diameter thereof thereby moving the lock ring into the suppressorgroove. Thus, as the collet is further moved forwardly, a gas seal iseffected between the collet, the sides of the suppressor groove 19 andthe open end 17 of the cap-like body, thereby to seal the suppressoropenings 7 and the barrel bore.

Although but two preferred embodiments of the present invention havebeen shown and described herein, it will be recognized by personsskilled in the art that variations and changes are possible within thespirit and scope of the present invention. Therefore, it is respectfullyrequested that the present invention not be regarded as limited in scopebut include all changes and modifications coming within the terms of theclaims hereof.

I claim:

1. A blank firing attachment for a rifle barrel the muzzle end of whichis provided with annular shoulder means, said attachment comprising acylindrical housing having one end thereof open and dimensioned toslideably fit over said shoulder means, Split sealing ring meansdisposed for engagement with the side of said shoulder means remote fromthe muzzle end of said barrel and in abutment with the open end of saidhousing, a collet surrounding said ring means and threadedly engagedwith cooperating means on the external surface of said housing adjacentto the open end thereof, the internal surface of said collet remote fromsaid cooperating means defining a cam surface for engaging said ringmeans whereby, in response to adjustment of said collet relative to saidhousing, said ring means is brought into sealing engagement with saidopen end and behind said shoulder means, and vent means disposed in saidcylindrical housing for controlled release of expanding gas pressures insaid barrel incident to firing.

2. The invention as defined in claim 1 and wherein said split sealingring means comprises a single ring having the body thereof diagonallysplit.

3. The invention as defined in claim 1 and wherein said split sealingring means comprises a pair of rings axially abutted with each other,the abutting surfaces thereof being flat, and each of said rings havingthe body thereof diagonally split, the diagonal splits of said ringsbeing disposed circumferentially spaced apart.

4. The invention as defined in claim 1 and wherein said vent meanscomprises a hole through said housing disposed apart from axialalignment with the bore of said barrel.

5. In an automatic weapon having a barrel and means associated with themuzzle end of said barrel providing an annular shoulder adjacent to andrearwardly of said muzzle end, a blank firing attachment for said weaponcomprising a cylindrical housing having one end thereof open anddimensioned to slideably fit over said annular shoulder, the oppositeend of said housing being disposed coextensive with said muzzle end andsaid associated means, split sealing ring means disposed for engagementwith the side of said shoulder remote from said muzzle end and inabutment with said open end, a collet encompassing said ring means and aportion of said housing adjacent said open end, cooperating means onsaid collet and said housing for effecting axial adjustment of saidcollet relative to said housing, the internal surface of said colletdefining a cam surface engageable with said ring means in response toadjustment of said collet relative to said housing, said cam surfacebeing effective to collapse said ring means into sealing engagement withsaid annular shoulder and said open end, and means in said housing forventing the expanding gases in said barrel incident to firing saidweapon.

6. The invention as defined in claim 5 and wherein said vent meanscomprises an opening in said housing disposed apart from axial alignmentwith said barrel bore and dimensioned for controlled release of saidexpanding gases.

7. The invention as defined in claim 6 and wherein said sealing ringmeans comprises a single ring having the body thereof diagonally split.

8. The invention as defined in claim 6 and wherein said sealing ringmeans comprises a pair of juxtaposed rings the adjacent surfaces thereofbeing flat and each of said rings having the body thereof diagonallysplit,

the diagonal splits thereof being disposed spaced apart. i t

1. A blank firing attachment for a rifle barrel the muzzle end of whichis provided with annular shoulder means, said attachment comprising acylindrical housing having one end thereof open and dimensioned toslideably fit over said shoulder means, split sealing ring meansdisposed for engagement with the side of said shoulder means remote fromthe muzzle end of said barrel and in abutment with the open end of saidhousing, a collet surrounding said ring means and threadedly engagedwith cooperating means on the external surface of said housing adjacentto the open end thereof, the internal surface of said collet remote fromsaid cooperating means defining a cam surface for engaging said ringmeans whereby, in response to adjustment of said collet relative to saidhousing, said ring means is brought into sealing engagement with saidopen end and behind said shoulder means, and vent means disposed in saidcylindrical housing for controlled release of expanding gas pressures insaid barrel incident to firing.
 2. The invention as defined in claim 1and wherein said split sealing ring means comprises a single ring havingthe body thereof diagonally split.
 3. The invention as defined in claim1 and wherein said split sealing ring means comprises a pair of ringsaxially abutted with each other, the abutting surfaces thereof beingflat, and each of said rings having the body thereof diagonally split,the diagonal splits of said rings being disposed circumferentiallyspaced apart.
 4. The invention as defined in claim 1 and wherein saidvent means comprises a hole through saiD housing disposed apart fromaxial alignment with the bore of said barrel.
 5. In an automatic weaponhaving a barrel and means associated with the muzzle end of said barrelproviding an annular shoulder adjacent to and rearwardly of said muzzleend, a blank firing attachment for said weapon comprising a cylindricalhousing having one end thereof open and dimensioned to slideably fitover said annular shoulder, the opposite end of said housing beingdisposed coextensive with said muzzle end and said associated means,split sealing ring means disposed for engagement with the side of saidshoulder remote from said muzzle end and in abutment with said open end,a collet encompassing said ring means and a portion of said housingadjacent said open end, cooperating means on said collet and saidhousing for effecting axial adjustment of said collet relative to saidhousing, the internal surface of said collet defining a cam surfaceengageable with said ring means in response to adjustment of said colletrelative to said housing, said cam surface being effective to collapsesaid ring means into sealing engagement with said annular shoulder andsaid open end, and means in said housing for venting the expanding gasesin said barrel incident to firing said weapon.
 6. The invention asdefined in claim 5 and wherein said vent means comprises an opening insaid housing disposed apart from axial alignment with said barrel boreand dimensioned for controlled release of said expanding gases.
 7. Theinvention as defined in claim 6 and wherein said sealing ring meanscomprises a single ring having the body thereof diagonally split.
 8. Theinvention as defined in claim 6 and wherein said sealing ring meanscomprises a pair of juxtaposed rings the adjacent surfaces thereof beingflat and each of said rings having the body thereof diagonally split,the diagonal splits thereof being disposed spaced apart.